Compare value ...

[Ioannis]

Try:

1.
ADCON0=%10000101
while !adcon0.2:wend

2.
Display your variables on LCD or a serial port to be sure what values they are

Ioannis

[cobuccit]

Try:

1.
ADCON0= 000101
while !adcon0.2:wend

with this the Pic16F88 not working

2.
Display your variables on LCD or a serial port to be sure what values they are

Display on LCD
24.5 °C
Tmin 16 Tmax 30

cdout $FE, 2, "Temp ",dec2 (temperature/100),".", dec1 (temperature//100),$DF,"C"
lcdout $FE, $C0, "Tmin ",#Tmin DIG 1,#Tmin Dig 0," Tmax ",#Tmax DIG 1,#Tmax Dig 0



My problem is, i think:
temperature is a word
Tmax is a byte

and I don't understand how compare the values

[Ioannis]

Don't you see? You display a decimal number but the number is in fact 245 and not 24.5!

So, maybe you can use word variables and multiply them by 10 so you can compare 245 to 160 and 300.

My first suggestion was to make sure that bit 0 of ADCON0 was set. It needs some time and if you go fast to start ADC, the module might not work as expected. I am sorry that I made the mistake of bit 0 to 2. Please include it as this:

ADCON0=%10000101
while !adcon0.0:wend

I would not set bit 2 at this stage but anyway.

Ioannis

[cobuccit]

ADCON0=000101
while !adcon0.0:wend

OK, Perfect this work well now

Don't you see? You display a decimal number but the number is in fact 245 and not 24.5!

So, maybe you can use word variables and multiply them by 10 so you can compare 245 to 160 and 300.

Ioannis

I have modified code in this mode, but don't work yet

If temperature > (Tmax*10) then
PORTA.6=1
else
PORTA.6=0
Endif

PORTA.6 go high when power on after showing the values on the display

NOTE :
The variables are still "temperature WORD" and "Tmax BYTE". I tried to change Tmax from BYTE to WORD in the declaration area but it gives me an error when compile

[Ioannis]

You should make it word. 30*10=300 > than a byte can hold.
Also better make the multiplication outside the comparison.

Use the LCD as a monitor to check your values.

About compilation, I guess it is a syntax error thing.

Ioannis

[cobuccit]

You should make it word. 30*10=300 > than a byte can hold.
Also better make the multiplication outside the comparison.

Use the LCD as a monitor to check your values.

About compilation, I guess it is a syntax error thing.

Ioannis

hi,

I have define Tcomp VAR WORD
and now i have :

tcomp=tmax*100

lcdout $FE, 2,   "Temp. ",dec2 (temperature/100),".", dec1 (temperature//100),$DF,"C "
lcdout $FE, $C0, "Tmax ",#Tmax DIG 1,#Tmax Dig 0," Tco ",dec2 (Tcomp/100),".", dec1 (Tcomp//100)

On display i see :

Temp. 23.5°C
Tmax 30 Tco 30.0

And PORTA.6 go at 1 the same

[louislouis]

on 10bit adc?

[richard]

correct 10 bit 1024 counts @5v vcc

[louislouis]

Here is the code. Look at the comments, and modify the RAW number to number when the display show 30.0degC.

define osc 4
adcon1.7=1
ANSEL = %000001 'Disable Inputs Tranne AN0
ADCON1 = %10001110 
OSCCON = %01100000 'Internal RC set to 4MHZ
TRISA =  %00000001 ' impostazioni INP/OUT
TRISB =  %00000000 ' delle porte
'----------------------------------------------------
DEFINE LCD_DREG PORTB       'Porta B DATA OUT 
DEFINE LCD_DBIT 4           '0 --> Bit 0-3 : 4 --> Bit 4-7 
DEFINE LCD_RSREG PORTB      'LCD register select port - Porta B --> RS
DEFINE LCD_RSBIT 2          'LCD register select bit  - Pin RS B2
DEFINE LCD_EREG PORTB       'LCD enable port - Porta B --> EN
DEFINE LCD_EBIT 3           'LCD enable bit - Pin EN B3DEFINE LCD_BITS 4           'LCD bus size 4 or 8 
DEFINE LCD_LINES 2          'Number lines on LCD DEFINE LCD_COMMANDUS 2000   'Command delay time in us 
DEFINE LCD_DATAUS 50        'Data delay time in us

Rele   VAR    PORTA.6     '                  Pin 15
'--------------------------------------------------------------
'---------Define ADCin Parameters   
DEFINE ADC_BITS 10      'set number of bits in result
DEFINE ADC_CLOCK 3      'set clock source (3=rc)
DEFINE ADC_SAMPLEUS 50  'Set sampling time in uS


'    RAM Assignments and Variables
'=========================================================================== 
temp var word
temperature var word
samples var word
sample VAR BYTE
quanta con 1250
Tmax VAR byte
Tmin VAR byte
'===========================================================================
Tmin=16
Tmax=30
 
START:
Lcdout $FE, 1

low rele

main:   
sample = 1
samples= 0
FOR sample = 1 TO 20 'Take 20 samples
ADCIN 0, temp 'Read AN0 into temp variable
samples = samples + temp
PAUSE 50 ' Wait 1/4 seconds per reading
NEXT sample
temp = samples/20 'Average over 20 samples (Every 5 seconds)
temperature= temp */ quanta

if temp > 675 then high rele  'Instead 675 write the correct RAW number for 30degC 
if temp < 675 then low rele   'Instead 675 write the correct RAW number for 30degC 

LCDOUT $FE, 2 ' ritorna al primo carattere
lcdout $FE, 2, "Temp ",dec2 (temperature/10),".", dec1 (temperature/10),"C"
'lcdout $FE, $C0, "Tmin ",#Tmin, " Tmax ",#Tmax            FOR NORMAL OPERATION UNCOMMENT LINE 
lcdout $FE, $C0, "RAW:",dec temp 'this show the ADC value  FOR NORMAL OPERATION COMMENT OR DELETE THIS LINE

'When the display show 30,0 degC look at the RAW number on LCD and rewrite it in lines: if temp > 675 then high rele
'and if temp < 675 then low rele . 

goto main

[richard]

not sure whats going on here

my LM35 has a 0.3 volt output @30c, adc value 61 [10mV/deg]

an adc read of 675 would need 329 deg

[louislouis]

I'm just curious, can you please try this hex, is It working OK?

[cobuccit]

I'm just curious, can you please try this hex, is It working OK?

No, it doesn't work, the relay goes ON as soon as I see the display and then it doesn't move anymore